LAUSR

Production systems commonly have multiple fill events in the nursery, which can lead to inaccurate feeding of dietary budgets. A simpler feeding program may provide practical benefits to producers. Five trials were conducted to compare nursery phase-feeding programs. Two treatments consisting of a 2-phase or a single-phase program were applied for 22 d postweaning. The 2-phase program consisted of a feed budget of 1.4 kg of a phase 1 diet formulated with 1.45% SID Lys and 5.4 kg of a phase 2 diet with 1.36% SID Lys. The single-phase program provided 6.8 kg of a unique diet with 1.38% SID Lys. Diets were corn, soybean meal, and whey permeate-based and contained 3,000 mg/kg Zn. All other nutrients met or exceeded the NRC (2012) recommendations. After the experimental period, pigs were fed a common diet for 23 d. In the five trials, 5,090 pigs were used with a total of 63 and 69 replicates per treatment for 2-phase and single-phase programs, respectively. There was no treatment × trial interactions (P > 0.10), thus data was combined for statistical analysis using SAS PROC MIXED. From d 0 to 22, pigs fed the single-phase program had higher (P = 0.041) ADFI and a tendency (P = 0.075) for higher BW. From d 22 to 45, pigs previously fed the single-phase program had a tendency (P = 0.057) for higher ADG. Overall (d 0 to 45), pigs fed the single-phase program had higher (P = 0.037) ADG and a tendency (P = 0.077) for higher final BW, with comparable (P > 0.10) ADFI and G:F to the 2-phase program. In conclusion, feeding a single-phase nursery program in the first 22 d postweaning resulted in higher overall ADG and similar ADFI and G:F compared to a 2-phase nursery program.